Centrifugal pump



3,@lA-59 Patented dan. 29, 1963 3,675,459 CENTRFUGAL PUMP Russell L.Hoeizer, Fairview Park, and George I. Schmidt,

Cleveland, Ghia, assignors to The Dow Chemical Ccmpany, Midland, Mich.,a corporation of Delaware Fiied .lune 17, 196), Ser. No. 36,864 6Claims. (Cl. lill-366) This invention relates to centrifugal pumps, andmore particularly to a centrifugal pump for use in lifting abrasiveand/or corrosive liquids a predetermined distance.

Centrifugal pumps generally have an impeller with radial 0r curved vanedsurfaces, the impeller being mounted upon a shaft and housed in a cavityof volute conformation. The impeller is necessarily closely fitted inthe housing cavity and mounted upon a shaft carried on bearings, whilesome type of seal means -is generally provided. Rapid wear of theimpeller, housing cavity, bearings and seal means will occur when theliquid being pumped is of an abrasive and/or corrosive nature. Inaddition, it is impossible to keep the bearings and seal meansadequately lubricated :because solvents contained in the liquid beingpumped, wash away the lubricants, which also can contaminate the liquidbeing pumped.

While the centrifugal pump of the invention may be advantageously usedin many applications, it will be found especially well suited for use incertain types of printing presses. Pumps generally used for circulatingsolvent type inks and coatings in the ink fountain of flexographic andgravure printing presses, are costly, involve excessive maintenance dueto wear and corrosion of seals and impellcrs, contaminate the ink withlubricant and foreign particles, and require frequent lubrication.Constant circulation of the ink is important for maintaining uniformcolor and consistency.

The centrifugal pump of the invention avoids the disadvantages andshortcomings of centrifugal pumps generally used on printing presses.More particularly, the centrifugal pump of the invention incorporatesthe following feature-s: no close fitting parts, thus eliminating wear;no contact or exposure of the ink to seals, bearings, or lubricants,hence, these elements of the pump, as well as the ink being circulated,are free of contamination; the pump is simple in structure, thusallowing low cost manufacture, and easy assembly and disassembly forcleaning, and, the pump is adaptable for direct mounting upon the inkfountain of a printing press, thereby eliminating hoses, tanks, andbuckets generally required by printing press pumps of the prior art.

Brietiy, the `centrifugal pump of the invention includes a smoothconical rotor, the upper end of which is closed, and has a plurality ofopenings about the periphery thereof, while the lower end of the rotoris positioned for irn- -mersion in the ink to be circulated. A collectorcup is arranged about the upper end of the rotor, which cup has apitcher spout through which the ink can pass by gravity to an inkfountain of the printing press. The pump operates on the simpleprinciple of centrifugal force, whereby rapid rotation of the rotorcauses the ink to be lifted upwardly and outwardly through the openingsat the upper end of the rotor. The pump operates only to lift liquid agiven amount; there is no pressurization of the liquid being pumped. Thevolume of liquid to be pumped may be varied by regulating of rotorspeed. The rotor is preferably rotated by lan air mot-or, when the pumpis used in the vicinity of inflammable solvents, such as are commonlyused in printing inks.

The main object of this invention is to provide a centrifugal pump foruse in handling abrasive -and/ or corrosive liquids.

A more specific object lof this invention is to provide a centrifugalpump for handling abrasive and/ or corrosive 2 liquid-s, which pump hasno close fitting parts, thus avoiding wear on the operative parts of thepump.

Another object of this invention is to provide a centrifugal pump forhandling abrasive and/ or corrosive liquids wherein the liquid beinghandled is free from Contact or exposure to seals, bearings, or pumplubricants, thus avoiding contamination of the pump parts, as Well asthe liquid being circulated.

Still another object of this 4invention is to provide a centrifugal pumpwhich eliminates the need for hoses, tanks and lbuckets generally usedwith pumps when applied upon the ink fountains of certain printingpresse-s.

Another object of this invention is to provide a centrifugal pump whichis simple in structure, thus allowing low cost manufacture, and easyassembly and disassembly.

These and further obiects and features of the invention will become moreapparent from the following description and the accompanying drawingwherein:

FIG. l is an elevation View, substantially in cross-section,illustrating a centrifugal pump representing an embodiment of theinvention, which pump is shown as applied to a printing press; and,

FIG. 2 is a section view generally as seen along line 2-2 in FIG. l.

Referring now to the drawing, the numeral 10 identifies `a pum-passemblage which includes -a rotor assembly l2, and a collector cup 14.The rotor assembly 12. includes a rot-or in the form of a smooth conicalcylindrical member lo which tapers toward an opening at the lower end,the upper end of the rotor being formed to provide a cylindricalenlargement 1S, anda hub member zii which encloses the upper end of therotor 16 and to which the rotor is securely affixed for verticalsuspension. The taper of the rotor 16 may be set according to pump, orlifting effect desired; in the disclosed application of the pump, ataper of approximately 5 was found to provide satisfac- 4tory results.While Ithe rotor has 4been described as having a smooth surface, itmaybe desirable, under certain conditions, to employ a surface that isnot exactly smooth. In any event, the main objective is to employ arotor configuration which will develop a lifting force upon the liquidas the rotor is caused to rotate. The lower surface Iof the hub memberZtl is tapered whereby an apex 22 thereof will coincide with thelongitudinal centerline of the rotor 16. A plurality of equi-spacedholes, or openings 24 are provided in the side Wall of the rotorcylindrical enlargement 18, the upper edge of said openings coincidingwith the outer edge of the tapered surface formed on the hub 20.

The Acollector cup 14 is formed to provide a flanged hole 26, the flangethereof extending upwardly and in spaced relation to the exterior of therotor 16. A side portion of the collector cup is formed to provide apitcher spout 28, which extends outwardly from the wall of the collectorcup to provide an opening 30 which is co-extensive with the lowersurface of the collector cup. A closure ring, or cover means 32 issecurely affixed to the collector cup 1d at the upper end thereof, whichclosure ring is adapted to support a motor means assembly 34. The motorassembly 34 includes a shaft 35, to which is secured a hub 3S adapted toreceive in snug engagement, the rotor hub member Zit. Holding means,such as set screws riti may be used to secure the hub member 2i? to thehub 38. The motor means 34 may be of any type as wiil provide high speedrotation of the shaft 36, however', when the centrifugal pump of theinvention is being used to handle inflammable, or explosive liquids, theuse of an explosion proof motor, such as an air motor would naturally berecommended. ln the illustrated arrangement, an air motor 42 is utilizedwhich is supplied with compressed air via a conduit, or pipe arrangement44.

While the centrifugal pump of the invention will be found to beextremely well suited for many applications, especially wherein theliquid to be handled is of an abrasive and/or corrosive nature, it willbe described as applied to a printing press for circulating Vsolventtype inks andv coatings, as used in flexographic and gravure Vprinting,As seen in FIG. 1, a pair of inlcing rolls, or rollers 46 and arearranged in rolling engagement, while a panmeansl -is supported beneaththe ink rolls by a pairof rod means 52, 54. The pan means 5d includes anink fountain portion 56, and a sump portion 5S. The

fountain portion 56 is adapted for maintenance of print ing inlr at avconstant level to assure a steady supply of ink'to the roll 43 which ispartially immersed therein.v Any ink supply to the fountain 56 in excessof predetermined requirements will flow into the sump portion 58,

as will be readily apparent.

The pump assemblage 1t) is aiixed to an adjustable mounting bracketassemblage 60 which is clamped upon the pan means Si? so that the lowerend of the rotor 16 is'immersedin the ink supply in the sump portionSt?,

while the pitcher spout 28 is arranged to discharge ink y into thefountain portion 56. A shield in the form of a cylindrical tube 62, maybe aflixed to the bracket assemblyinconcentricspaced relation to therotor 16, which shield 62 extends downwardly a given distance below thesurfaceof the' ink-in thesumpportion 5S.

The operation of the centrifugal pump of the inventionis-extremelysimple fonthe pumping andcirculatingof printing ink. Thepump operateson the simple. principle of centrifugalforce; rapidrotation of the rotor 16 causes the; inlei to be liftedupwardlywithinthe rotor and `discharged lor expelled 'radiallythroughthe rotor openingsf.

24.1The inlt thus expelled, will be caught, in the collector-cup ,fromwhence it willow by gravity through the g' s pout,opening,tlginto theink fountain 56. The volumegof liquid -to be pumped or circulated,v maybe easily regulatedby controllingthespeed of the motor 4t2, which,

in thecase of ,an airgnoton involves noV more than the adjustment of anair Yllowyalve.V

Front/thev foregoing, it willbe appreciated that the centrifugal pumpofthe invention may be used to realize. ally of v the objectives set forthin the early partof this y disclosure.

"[hev foregoing description has been Vgiven 4in detaill withoutthoughtof limitation since theinventive principlesinvolved are capable ofassuming otherforms'with-v out .departing from the spirit of theinvention or the scope of the following claims. Whatis claimed is:

l. A .centrifugal pump for raising liquids; including, a hollow rotorhaving a smooth interiorV surface which tapers toward an opening at thelower extremity, ,a hub` means attheupper extremity of the rotor, saidhub means being arranged .forthevertical suspension of said rotor,V

2. A centrifugal pump for raising liquids including,

a smooth interiorV hollow conical rotor tapering toward an opening atthe lower extremity and having a cylindrical enlargement at the oppositeextremity, a hub meanssecuredI to and enclosing said cylindricalenlargement and being narranged for the vertical suspension of therotor,

said rotor being formed to provide openings adjacent said hub means toallow radial discharge of liquid raised upwardly within the rotor due torotation thereof, and a collector cup surrounding the upper end of saidrotor for receiving the liquid discharged from said openings, saidcollector cup being formed to provide a flanged opening for receiving inspaced relation said rotor and being further formed to provide anopening to allow egress of liq uid from the collector cup.

3. A centrifugal pump for raising liquids including, a smooth interiorhollow .conical rotor tapering toward an opening at the lower extremityand having a cylindrical enlargementat the opposite extremity, a hubmeans secured to and enclosingsaid cylindrical venlargeafnent and beingarranged for the vertical suspension of the rotor,

said rotor being formed to provide a plurality of openings adjacent saidhub means to allow radial discharge of liquid raised upwardly within therotor due to rotation thereof, a collector cup surrounding the upper endof said from the collector cup, and a covermeans for said col-- lectorcup, said cover-means being arranged for support of a motormeans'operable for rotation of said rotor.v

4. A centrifugal pump according to claim 3, wherein a shield-means inthefformr of a cylindrical tube is arranged.y below the collectorcupandin spaced relation to said rotor.

5. A printing press roll-inking Yarrangement comprising in combination,an inkingl roller, a constant level ink fountain .which formspart of apan means including a sump portion which receives overflow inkfrom theink'- fountain, a rotor assembly including al smooth interiorhollow`conical rotor. tapering toward an opening at the lowerextremityandnhaving acylindrical enlargement at the opposite extremity,a hub means secured to and enclosing saidecylindrical enlargement-andbeing arrangedY for thevertical suspension of the rotor, said.rotorbeing formedto provide .a plurality of openings adjacent saidhubmeanstoallow radial discharge of liquid raised upwardly withintherotor due to rotation thereof, acollector cup surrounding the upperend of said rotor for receiving the ,liquiddischarged fromsaidopenings,said collector cup being formed to provide a flanged*k opening inspacedrelation lto saidrotor, the flange of said openingextendingupwardly, saidcollector. cup being furtherarranged vto vprovidea pitcher spout having f an .opening whichis positionedl above the inkfountain, and a bracket meansgfor` supporting the centrifugal pumpassemblage so that the lower end of the rotor will .be immersed. in abody of inkin thesurnp portion.,

6. A centrifugalpurnp-accordingto claim 5, wherein a cover means isarranged atop said collector cup, which cover means is, adapted forthe,support of amotor meansV operable for'rotation of Saidrotor.,

References Cited in the le of this patent UNlTED STATES PATENTS 342,723Ancira May 25, 1886 1,431,350 Woodyv .Oct. l0, 1922 1,995,701y ButtnerMar. 26,fl935 2,419,905 Miess Apr.r 29, 1947 2,650,537 Rosse Sept., l,1953y 2,783,088 Butler Feb.v 26, 1957

5. A PRINTING PRESS ROLL INKING ARRANGEMENT COMPRISING IN COMBINATION,AN INKING ROLLER, A CONSTANT LEVEL INK FOUNTAIN WHICH FORMS PART OF APAN MEANS INCLUDING A SUMP PORTION WHICH RECEIVES OVERFLOW INK FROM THEINK FOUNTAIN, A ROTOR ASSEMBLY INCLUDING A SMOOTH INTERIOR HOLLOWCONICAL ROTOR TAPERING TOWARD AN OPENING AT THE LOWER EXTREMITY ANDHAVING A CYLINDRICAL ENLARGEMENT AT THE OPPOSITE EXTREMITY, A HUB MEANSSECURED TO AND ENCLOSING SAID CYLINDRICAL ENLARGEMENT AND BEING ARRANGEDFOR THE VERTICAL SUSPENSION OF THE ROTOR, SAID ROTOR BEING FORMED TOPROVIDE A PLURALITY OF OPENINGS ADJACENT SAID HUB MEANS TO ALLOW RADIALDISCHARGE OF LIQUID RAISED UPWARDLY WITHIN THE ROTOR DUE TO ROTATIONTHEREOF, A COLLECTOR